This invention relates to improved flow control valves for switching fluid flow among multiple flow conduits, and more particularly relates to improved valve control of oxygen concentrator systems and improved operation of such systems.
Valve control systems for cycled switching between multiple fluid processing units such as dual molecular sieve beds for oxygen separation from air have been described for example in U.S. Pat. No. 4,925,464 which is incorporated by reference herein. This patent describes control valve structure employing two valve members which have respectively engaged surfaces which are relatively rotatable to provide valving action and cycled operation of the dual molecular sieve bed processing units. The relative rotation of the valve members is driven in a continuous manner and performs modulated flow switching with simple and reliable cycle frequency.
The present invention provides improved efficiency in the cycled processing of such systems with an improved valve structure providing additional process flow functions.